This is an R21 application in response to RFA DA-02-001 entitled "Neuroimaging Technology Development to Assess Brain and Behavior in Pediatric Populations". The proposal focuses on neuroimaging technology development in the context of examining maturation of reward and prediction circuitry. This frontostriatal circuitry is thought to be centrally involved in 1) addictive and impulsive behaviors relevant to substance abuse; and 2) repetitive or sequenced actions relevant to probabilistic and reward learning. We will examine the normal development of this circuitry and how it may be modified with experience using a converging methods approach. The Institute consists of faculty with expertise in the use of structural and functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), electroencephalographic (EEG) and evoked potential recording (ERP) techniques with typically and atypically developing children. The proposed studies involve the combined use of these technologies in both a hypothesis- and design-driven program of research. We will test specific hypotheses regarding the development and function of frontostriatat circuitry in the context of prediction and reward. Hypothesis testing will occur in the context of behavioral paradigm and design development for use with typically and ultimately atypically developing populations (e.g., substance abuse, prenatal exposure to substances). This work is innovative in that relatively little is known about the normal development of reward/prediction circuitry in humans. Understanding the normal development of this circuitry and how it may be modified with experience during sensitive periods of development is essential work that has direct implications for understanding basic mechanisms of substance abuse and maladaptive learning in children. The proposed studies will lay the critical groundwork, both scientific and methodological, for subsequent studies on substance abuse in children.